478 A rare case of right ventricular ischaemia and ventricular tachycardia in neonate caused by intermittent occlusion of origin of the right coronary artery by an echogenic mass

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Abstract OnBehalf Cornwall A term neonate with poor condition at birth was noted to be markedly bradycardic when crying. ECG showed first degree heart block. Echocardiogram demonstrated poor bi-ventricular function. He was treated for Hypoxic ischemic encephalopathy (HIE). In the next few hours he developed short episodes of ventricular tachycardia with left bundle branch block and non-conducted P waves suggesting an origin of tachycardia from the right ventricle. His repeat ECHO suggested that he had right ventricular infarction due to a very rare finding of intermittent occlusion of the origin of the right coronary artery by an echogenic mass. He was transferred for emergency cardiac surgery to remove a clot of 1.6cm, occluding the right coronary artery. Histology findings were in keeping with a thrombus. Thrombophilia screen for both parents and infant were negative. MRI Brain did not show evidence of HIE suggesting his poor condition at birth was secondary to intermittent coronary ischemia. Discussion: Myocardial infarction (MI) in neonates is a rarely encountered and potentially life-threatening condition, with mortality rate as high as 90%. We present one of the first reported cases of successful surgical management of an acute right coronary artery thrombosis after an early diagnosis. The cause of thrombosis remains unclear in our patient. They were born in poor condition with initial pH 6.9 and lactate of 10, but with a structurally normal heart and negative thrombophilia screen. Perinatal asphyxia is a potential cause; however there is doubt that this may be a symptom rather than cause of the right coronary artery occlusion. Early diagnosis was key in management after a high level of clinical suspicion. He made significant recovery with near normal RV function, and is currently on captopril and carvedilol post-surgery. This is one of the first cases to document near full return of cardiac function following ischaemia to the right ventricle Abstract 478 Figure. 5